naphthalene+OCH3+NO2 C11H9NO3

B_1049b24064 · SMILES COc1cc([N+](=O)[O-])cc2ccccc12 · InChIKey BCAWRAILVSDAAU-UHFFFAOYSA-N

Cheap level done

finite-difference Hessian noisy

finite-difference Hessian noisy (analytic check differs > 15 cm⁻¹). The finite-difference Hessian and the analytic Hessian of the same geometry differ by more than 15 cm⁻¹ on at least one frequency; the numerical route is the noisy one.

Infrared spectrum at the cheap level (B3LYP/6-31G*, the pipeline's input)

cheap input (B3LYP) bands

How to read this

48 infrared-active bands (500–3500 cm⁻¹); the strongest at 1387 cm⁻¹ (7.2 µm), 307 km/mol.

cheap input (B3LYP): blue curve, sticks orange at the curve's peak scale. Lorentzian, FWHM 10 cm⁻¹; axis in km mol⁻¹ per cm⁻¹.

Band heights from the molecule's dipole derivatives and the same B3LYP Hessian as the listed positions (double harmonic).

Predicted spectrum (rung 3, the learned correction): computed by the pipeline, not drawn on this page; licensed for ring-ip, CH-stretch, CH-oop (decision 65).

How well is this shape known?

measured on (ΔH network v1.3)	spectrum overlap cheap → corrected	height error cheap → corrected
8 unseen simple aromatics (layer A), DFT stand-in for the higher level	0.28 → 0.98	0.23 → 0.10
31 molecules of unseen scaffolds, DFT stand-in for the higher level	0.37 → 0.97	0.51 → 0.24
against coupled cluster	not measured for this version

Overlap: similarity of the two broadened spectra (1 = the same shape). Height error: relative error per band, weighted by height (0 = the same heights). "Corrected" is the learned correction on molecules it never saw; the pipeline serves it for the licensed families. Open: the dipole derivatives themselves are computed at the cheap level (on benzene they differ from coupled cluster by about 20 %).

Structure

2D depiction from the SMILES.

Status ladder

Listed
Cheap level done — 2026-09-26, ubuntu-32gb-hel1-21
Correction predicted — not yet: the learned layer is training
Spectrum predicted — not yet: the learned layer is training
Anchored
Validated

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Not available on this site yet: the pipeline (a molecule in, its spectrum and certificate out) runs on the project's own computer, with three of the four mode families licensed at the DFT stand-in level. Sign-in will be needed only to request runs; reading stays open.

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Harmonic frequencies at the cheap level (deck v1: B3LYP and ωB97X, 6-31G*, at the B3LYP geometry)

66 vibrational modes; imaginary modes negative. Shift = ωB97X − B3LYP; height = B3LYP band height (km/mol).

The B3LYP bands are drawn in the spectrum above; the table adds their heights, the ωB97X positions and the shift.

#	B3LYP (cm⁻¹)	height (km/mol)	ωB97X (cm⁻¹)	shift
1	55.4	0.14	110.5	+55.1
2	87.2	3.76	115.9	+28.7
3	93.5	0.01	127.1	+33.6
4	167.9	3.20	182.3	+14.4
5	168.0	3.40	185.0	+16.9
6	194.5	0.75	212.3	+17.8
7	209.4	0.92	218.9	+9.5
8	259.8	1.66	288.4	+28.6
9	308.1	0.24	322.6	+14.6
10	340.8	0.52	348.0	+7.2
11	345.1	0.36	355.3	+10.1
12	439.8	1.80	448.3	+8.5
13	445.0	2.44	457.3	+12.3
14	501.9	1.91	515.2	+13.3
15	511.1	1.56	518.0	+6.9
16	543.3	1.23	550.5	+7.2
17	582.8	2.85	597.0	+14.3
18	610.5	5.71	616.1	+5.7
19	637.1	5.14	642.1	+5.0
20	643.2	3.76	657.4	+14.2
21	748.6	2.29	766.1	+17.5
22	770.9	21.29	781.5	+10.5
23	778.7	46.09	794.7	+16.0
24	791.4	10.57	807.1	+15.7
25	802.6	24.68	814.3	+11.7
26	866.6	6.23	879.8	+13.2
27	886.4	6.95	899.1	+12.7
28	890.1	8.47	906.2	+16.1
29	917.6	22.31	943.0	+25.4
30	960.3	6.69	976.0	+15.7
31	968.9	2.89	1001.3	+32.4
32	999.5	0.00	1031.1	+31.6
33	1023.3	12.68	1037.1	+13.8
34	1057.1	8.64	1068.5	+11.5
35	1117.6	70.00	1131.7	+14.1
36	1147.3	84.52	1158.3	+11.1
37	1184.1	5.81	1175.6	-8.5
38	1184.7	0.94	1194.6	+9.9
39	1199.2	14.17	1207.6	+8.4
40	1221.7	1.78	1222.9	+1.2
41	1239.6	19.58	1240.4	+0.8
42	1273.8	29.67	1275.1	+1.3
43	1314.0	77.94	1319.1	+5.1
44	1387.2	307.43	1384.9	-2.3
45	1395.3	152.04	1430.6	+35.3
46	1418.4	80.00	1437.3	+19.0
47	1441.1	56.01	1450.8	+9.7
48	1480.1	47.58	1491.8	+11.7
49	1491.9	15.84	1505.6	+13.7
50	1511.3	9.19	1525.2	+13.8
51	1520.5	6.85	1532.0	+11.4
52	1533.7	27.36	1543.7	+10.0
53	1566.7	61.08	1595.0	+28.4
54	1620.5	171.58	1646.6	+26.1
55	1639.9	65.12	1669.2	+29.4
56	1666.3	31.18	1695.7	+29.4
57	1680.8	16.59	1726.3	+45.4
58	3037.2	46.85	3072.3	+35.1
59	3101.3	32.47	3148.6	+47.3
60	3167.5	18.93	3210.3	+42.8
61	3187.7	0.11	3230.3	+42.6
62	3197.3	13.33	3239.9	+42.6
63	3211.1	25.24	3253.6	+42.5
64	3235.5	6.28	3279.1	+43.6
65	3247.1	1.46	3289.9	+42.8
66	3277.3	6.62	3321.7	+44.4

Second route

Analytic Hessian (pyscf, grid 99/590) against the corpus finite differences: b3lyp max |Δω| 1 cm⁻¹; wb97x max |Δω| 15 cm⁻¹.

Provenance

Releases: none yet
Entered the corpus as: cores with one or two substituents, enumerated from the parents (layer B)
Run: ubuntu-32gb-hel1-21, 2026-09-26 08:35:00 → 2026-09-26 10:01:58, 5218 s, peak 5.54 GB, deck 9e27bf8e9348
Imaginary modes: B3LYP 0, ωB97X 0
Cheap-level band heights: dipole derivatives dipole_b3lyp_cphf.npz, Hessian hessian_b3lyp.npz
Source files: corpus factory · manifest